Circuit for use with display devices and power supplying method

ABSTRACT

An embodiment is a circuit for use with a display device, the circuit including: a first input node configured to be operatively coupled to a first port of a data source device that provides the display device with data, to receive a first direct voltage used for a real-time display of the data on the display device; and at least one output node, configured to operatively provide the display device with at least one output voltage generated based on the first direct voltage, wherein the first port is isolated from a data port used to transmit the data.

PRIORITY CLAIM

The instant application claims priority to Chinese Patent Application No. 201110115508.2, filed Apr. 27, 2011, which application is incorporated herein by reference in its entirety.

TECHNICAL FIELD

An embodiment relates generally to electronic circuits, and more particularly to a circuit for use with display devices and a method for supplying power.

BACKGROUND

To support various signal formats, current computers and audio/video apparati, for example DVD players, provide various data ports, for example USB (Universal Serial BUS) Port, VGA (Video Graphics Array) Port, HDMI (High-Definition Multimedia Interface) Port, DP (Display Port) Port, etc. The ports not only enable data transmission, but also supply power to some low-power-consumption devices, such as mobile phones, digital cameras, mouses, etc.

FIG. 1 shows an example in which a computer 10 supplies power to and transmits data to a mouse 11 via a USB port 12. As shown, the mouse 11 includes a voltage converter 13 and a microprocessor unit (MCU) 14. The USB cable encases four wires: a power supply wire 15, a ground wire 16, a positive data wire 17, and a negative data wire 18 (e.g., for differential data transmission). Wires 15 and 16 are coupled to the voltage converter 13 of the mouse 11 to obtain operating voltages for modules of the mouse 11, and the data wires 17 and 18 are coupled to the MCU 14 of the mouse 11 to enable data transmission between the mouse 11 and the computer 10.

In the configuration of FIG. 1, the port 12 not only enables the data transmission between the computer 10 and the mouse 11, but also enables power to be supplied from the computer 10 to the mouse 11. However, the power supplied via USB Port, DP Port, or HDMI Port is very limited because such power is mainly aimed at supporting data transmission. For example, a USB power wire typically provides a voltage of 5V, and the upper limit of current is generally about 950 mA. For another example, a DP Port typically provides a power of about 1.5 W. After it is coupled with a computer or an audio/video apparatus, the display device may fail to normally display the audio/video, operate unstably, or fail to operate in an optimum state if it operates by only using the power supplied via ports like a USB Port. Therefore, display devices usually also need to be coupled to another power source such as commercial power. However, this may lead to inconvenience during use. For example, positioning of the display device is restricted not only by data wires between the display device and the audio/video apparatus, but also by its own power-supply wire. In addition, there may be limited power sockets such that the audio/video apparatus and the display device cannot be used simultaneously.

SUMMARY

Thus, there is a need for improved circuit and method for supplying power to a display device.

In an embodiment, there is provided a circuit for use with a display device. The circuit includes a first input node, configured to be operatively coupled to a first port of a data source device that provides the display device with data, to receive a first direct voltage used for a real-time display of the data on the display device; and at least one output node, configured to operatively provide the display device with at least one output voltage generated based on the first direct voltage. The first port is isolated from a data port used to transmit the data.

In another embodiment, there is provided a DC-DC converter. The DC-DC converter includes a circuit according to an embodiment of the disclosure.

In still another embodiment, there is provided a circuit for use with a data-source device, wherein the data-source device is configured to provide a display device with data. The circuit includes a first output node, coupled to the display device via a first port, to provide the display device with a first direct voltage used for a real-time display of the data on the display device. The first port is isolated from a data port used to transmit the data.

In still another embodiment, there is provided a method. The method includes coupling a display device to a data-source device that provides the display device with data via a power supply wire isolated from a data wire, to enable the display device to receive a first direct voltage from the data source device. The first direct voltage is used for a real-time display of the data on the display device.

The foregoing has outlined, rather broadly, features of the present disclosure. Additional features of the disclosure will be described hereinafter. It should be appreciated by those skilled in the art that the conceptions and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures or processes for carrying out the same purposes. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and advantages described herein, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

FIG. 1 shows an example where a computer supplies data and power to a mouse via a USB port.

FIG. 2 shows a schematic drawing of a circuit for use with a display device according to an exemplary embodiment of the disclosure.

FIG. 3 shows another exemplary position of the first port of FIG. 2 on the data-source device.

FIG. 4 shows an exemplary configuration of the port 31 of FIG. 3.

FIG. 5 shows an exemplary configuration of the circuit of FIG. 2.

FIG. 6 shows a schematic drawing of a circuit for use with a display device according to another exemplary embodiment of the disclosure.

FIG. 7 shows an exemplary configuration of the circuit of FIG. 6 including a switch module.

FIG. 8 shows another exemplary configuration of the circuit of FIG. 6 including a switch module.

FIG. 9 shows a schematic drawing of a circuit for use with a data source device according to an exemplary embodiment of the disclosure.

FIG. 10 shows a schematic drawing of a circuit for use with a data source device according to another exemplary embodiment of the disclosure.

FIG. 11 shows an exemplary combination of the circuit of FIG. 2.

FIG. 12 shows an exemplary modification on the circuit of FIG. 2.

Corresponding numerals and symbols in different figures generally refer to corresponding parts unless otherwise indicated. The figures are drawn to clearly illustrate the relevant aspects of embodiments of the present disclosure and are not necessarily drawn to scale. To more clearly illustrate certain embodiments, a letter indicating variations of the same structure, material, or process step may follow a figure number.

DETAILED DESCRIPTION

The implementation and usage of embodiments are discussed below in detail. It should be appreciated that the specific embodiments discussed are merely illustrative of specific ways to implement and use concepts discussed in this disclosure invention, and do not limit the scope of this disclosure.

FIG. 2 shows a schematic drawing of a circuit 24 for use with a display device according to an exemplary embodiment of the disclosure. In FIG. 2, by way of example, the circuit 24 is used with a display device 21. As shown, the circuit 24 is included in a power supply module 23 of the display device 21. The display device 21 mainly includes a power-supply module 23, a controller 25, a data receiving module 26, a signal processing module 27, a display module 28 and a backlighting module 210. The display device 21 may be, for example, a liquid-crystal display (LCD), a plasma display, etc.

In operation, a first input node 241 of the circuit 24 is coupled to a first port 201 of a data-source device 20 (for example, a computer, a DVD player, etc.) via a power supply wire 291 to receive a first direct voltage, and the other power supply wire 292 is grounded to provide a reference voltage. The circuit 24 further includes at least one output node 242 to output at least one output voltage based on the first direct voltage. The configuration of the circuit 24 will be exemplarily illustrated hereinafter. The power-supply module 23 including the circuit 24 supplies power to the controller 25 and, under the control of the controller 25, supplies power to the data-receiving module 26, the signal-processing module 27, the display module 28, and the backlighting module 210. The data-receiving module 26 receives data to be displayed from a data port 22 of the data-source device 20. Depending on the data format, the data port 22 may be a HDMI Port, or a DP Port, etc. The data can be transmitted to the data-receiving module 26 via multiple data wires 293 . . . 294. The data-receiving module 26 typically includes a decoder to decode the received data and to obtain a video signal, audio signal, and synchronizing signal. The signal-processing module 27 typically includes a scaler, receives a video signal from the data-receiving module 26, and converts the video signal into a format suitable for displaying on the display device 21.

Specifically, the first input node 241 may be coupled to, for example, a peripheral connector of the data-source device 20 to obtain a direct voltage of 12V or 5V, which is used for a real-time display of the data from the data-source device 20 on the display device 21.

One or more of the following advantages may be realized by employing an embodiment of the circuit 24 of FIG. 2.

First, because the first port 201 is isolated from the data port 22, the first port 201 doesn't need to conform to Data Port Specifications of the data port 22, which provides flexibility in design of the first port 201. Depending on the power consumption of the display device 21, the first port 201 may be coupled to one of the multiple output voltages provided by the power-supply module of the data-source device 20. In this way, the first input node 241 of the circuit 24 coupled to the first port 201 can obtain enough power. Thus, situations where the display device fails to normally display the audio/video, operates unstably, or fails to operate in an optimum state, which may be caused by supplying power via power wires of a data port (as shown in FIG. 1), can be avoided.

In addition, because it employs the circuit 24, the display device 21 doesn't need to be coupled to a commercial power socket, which means that an AC-DC converter is not necessary and provides flexibility in design of the display device. For example, because the power-supply module 23 doesn't include an AC-DC converter, the power-supply module 23, the controller 25, and the data-receiving module 26 can be located on one circuit board. Therefore, the space that is otherwise occupied by cables coupled between circuit boards and the labor for connecting such cables are saved. Furthermore, the modules, such as the power-supply module 23, the controller 25, and the data-receiving module 26, can be integrated in one chip, and signal delay caused by wiring between chips is reduced or eliminated.

Additionally, because an AC-DC converter is not necessary, energy loss due to AC-DC converting can be avoided, which promotes low-carbon emissions.

Furthermore, the display device 21 can be thinner without an AC-DC converter. Because the display device 21 doesn't need to be coupled to commercial power, it isn't restricted by commercial-power wires during positioning.

It should be appreciated that the first port 201 being isolated from the data port 22 means that the first port 201 is electrically isolated from the data port 22. In operation, the ports 201 and 22 can be placed in different interface connectors of the data-source device 20. Alternatively, the ports 201 and 22 can be placed in the same interface connector of the data-source device 20.

As shown in FIG. 3, the first port 201 and the data port 22 are placed in one connector 31 of the data-source device 20, i.e., viewed from the outside of the data-source device 20, power supply wires 291 and 292 and data wires 293 . . . 294 are led out from the same connector 31.

FIG. 4 shows an exemplary configuration of the connector 31 of FIG. 3 in which the data port 22 is a DP Port. The connector 31 includes 22 pin sockets, wherein the pin sockets 41 and 42 correspond to the first port 201, and the other 20 correspond to the data port 22. Specifically, one end of the power supply wire 291 is coupled to the pin socket 41 and the other end is coupled to the first input node 241 so that the first input node 241 can obtain the first direct voltage from the data-source device 20.

It should be appreciated that although FIG. 4 shows that the first port 201 includes a pair of pin sockets 41 and 42 for the purpose of supplying power, the first port 201 can include multiple pairs of such pin sockets, respectively coupled to multiple pairs of power and ground wires, to provide more power.

Additionally, the power wires 291 and 292 and the data wires 293 . . . 294 led out from the connector 31 can be encapsulated in one cable. The cable has a connector corresponding to the connector 31 on the end for connecting to the data-source device 20 and a same (or similar) connector on the other end for connecting to the display device 21. Accordingly, the display device 21 has a connector that is the same as or similar to the connector 31 shown in FIG. 4 so as to be coupled with the connector of the cable encapsulating the power wires 291 and 292 and the data wires 293 . . . 294. Being so configured, when viewed from the outside, there exists only one cable between the data source device 20 and the display device 21. Alternatively, the cable may be a single one near the data-source device 20 and split into two branches near the display device 21, one branch encapsulating the power wires and the other branch encapsulating the data wires, so that the cable has two connectors on the end adjacent the display device 21. Accordingly, the display device 21 is provided with two connectors for coupling to the cable.

It should be appreciated that the circuit 24 may be realized by a low-dropout (LDO) linear voltage regulator, or a step-down DC-DC converter (Buck converter), etc. FIG. 5 shows an exemplary construction of DC-DC converter circuit 24.

As shown, the circuit 24 includes a switch 51, an inductor 52, and a diode 53. In operation, the first input node 241 of the circuit 24 is coupled to the first port 201 of the data-source device 20 (as shown in FIG. 2) to receive a first direct voltage, for example, 12V or 5V. The switch is controlled by a PWM signal 54. When the switch 51 is closed, the inductor 52 is charged. When the switch 51 is opened, the inductor 52 is discharged through the diode 53 and a load (not shown) externally coupled between the output node 242 and the reference line. There may also be a bypass capacitor coupled between the node 242 and the reference line. By changing the duty ratio of the PWM signal 54, different regulated output voltages can be realized, for example, the first direct voltage can be converted to 3.3V, or 1.2V, etc.

It should be appreciated that, the construction in FIG. 5 is just exemplary, but not restrictive. The particular construction of the circuit 24 is not a limiting factor of the disclosure, and the circuit 24 can be implemented using any suitable circuit that implements voltage conversion.

FIG. 6 shows a schematic drawing of a circuit 64 for use with a display device according to another exemplary embodiment of the disclosure. In FIG. 6, by way of example, the circuit 64 is used with a display device 61. As shown, the circuit 64 is included in a power-supply module 63 of the display device 61. The display device 61 mainly includes the power-supply module 63, a controller 65, a data-receiving module 66, a signal-processing module 67, a display module 68, and a backlighting module 620. The display device 61 may be, for example, a liquid-crystal display, a plasma display, etc.

In operation, a first input node 641 of the circuit 64 is coupled to a first port 601 of a data source device 60 (for example, a computer, a DVD player, etc.) via a power-supply wire 691 to receive a first direct voltage, and the other power-supply wire 692 is grounded to provide a reference voltage. The circuit 64 further includes a second input node 643, coupled to an external power supply 610 via a power-supply wire 611, to receive a second direct voltage. The circuit 64 further includes a switch module 644 coupled between the first input node 641, the second input node 643 and the output node 642, configured to operatively switch between the first input node 641 and the second input node 643. When the switch module 644 is switched to the first input node 641, the circuit 64 receives the first direct voltage and the output node 642 outputs a voltage based on the first direct voltage. When the switch module 644 is switched to the second input node 643, the circuit 64 receives the second direct voltage and the output node 642 outputs a voltage based on the second direct voltage. Configuration of the switch module 644 and the circuit 64 will be described illustratively hereinafter. The power-supply module 63 including the circuit 64 supplies power to the controller 65 and, under the control of the controller 65, supplies power to the data-receiving module 66, the signal-processing module 67, the display-module 68, and the backlighting module 620. The data-receiving module 66 receives data to be displayed from a data port 62 of the data-source device 60. Depending on the data format, the data port 62 may be a HDMI Port, or a DP Port, a VGA port, etc. The data can be transmitted to the data-receiving module 66 via multiple data wires 693 . . . 694. The data-receiving module 66 typically includes a decoder to decode the received data and to obtain video signal, audio signal, and synchronizing signal. The signal-processing module 67 typically includes a scaler, receives a video signal from the data-receiving module 66, and converts the video signal into a format suitable for displaying on the display device 61.

Specifically, the first input node 641 may be coupled to, for example, a peripheral connector of the data-source device 60 to obtain a direct voltage of 12V or 5V. The second input node 643 may be coupled to an adapter, for example, which receives an alternating voltage of 110 VAC or 220 VAC and outputs a direct voltage of 12V or 5V.

In addition to the one or more advantages that can be realized by the circuit 24 of FIG. 2, the circuit 64 shown in FIG. 6 may also be advantageous in the case where the display device 61 may need an external power supply. Because the switch module 644 is switched to one of the first input node 641 and the second input node 643, a short circuit between the power-supply module of the data-source device 60 and the external power supply 610 can be prevented even if the circuit 64 is coupled to both the first port 601 of the data-source device 60 and the external power supply 610 in an error operation.

FIG. 7 shows an exemplary construction of the circuit of FIG. 6 including a switching module. In the example, the circuit 64 is shown as a DC-DC voltage converter in a pin package. The circuit includes a switch 71 coupled between a voltage input pin 75 and an inductor pin, an external inductor 72 coupled to the inductor pin, a diode 73 coupled between the inductor pin and the ground pin, and a switch module 644 couple to the voltage input pin 75. As shown, the switch module 644 is shown as including a first diode 76 and a second diode 77, respectively coupled to the first input node 641 and the second input node 643.

In operation, the switch module 644 is switched to the first input node 641, i.e., the first diode 76 is turned on and the second diode 77 is turned off, if the voltage at the first input node 641 (the first direct voltage) is higher than the voltage at the second input node 643 (the second direct voltage). Alternatively, the switch module 644 is switched to the second input node 643, i.e., the first diode 76 is turned off and the second diode 77 is turned on, if the voltage at the first input node 641 (the first direct voltage) is lower than the voltage at the second input node 643 (the second direct voltage).

For example, if the first direct voltage is 12V, the second direct voltage is 11.6V, and the forward voltage drop of the first diode 76 and the second diode 77 is 0.3V, then the voltage at the input pin is 11.7V, the first diode 76 is turned on and the second diode 77 is turned off. Therefore, a short circuit between the data-source device 60 and the external power supply 610 is prevented even if the circuit 64 is coupled to both the first port 601 of the data-source device 60 and the external power supply 610.

It should be appreciated that, the encapsulated DC-DC voltage converter shown in FIG. 7 is just illustrative, but not restrictive. Those skilled in the art would understand that a DC-DC voltage converter typically includes delay units and a controller to control the opening and closing of the switch 71 based on an output of a comparator. For simplicity, the controller, the comparator, and other components of the DC-DC converter are not shown in FIG. 7.

FIG. 8 shows another exemplary construction of the circuit of FIG. 6 including a switching module. The circuit 64 is still shown as a DC-DC voltage converter in a pin package. In comparison with that of FIG. 7, the switch module 644 is integrated on package in the example of FIG. 8. As shown, the DC-DC voltage converter includes a first input pin 75 and a second input pin 76, respectively leading out the first input node 641 and the second input node 643. When the first direct voltage is higher than the second direct voltage, the output node 642 outputs a voltage generated based on the first direct voltage. When the first direct voltage is lower than the second direct voltage, the output node 642 outputs a voltage generated based on the second direct voltage.

It should be appreciated that, the DC-DC voltage converter can employ package types other than the pin type shown in FIG. 8, for example, a Ball-Grid_Array (BGA) package. When employing a BGA package, the first input node 641 and the second input node 643 can be respectively led out by a first solder ball and a second solder ball.

It should be appreciated that although the switch module is described as being used with DC-DC voltage converters in FIGS. 7 and 8, the switch module can be used with other voltage-converting circuits, for example, a LDO linear voltage regulator.

It should be appreciated that the construction of the switch module 644 shown in FIGS. 7 and 8 is just illustrative, and the switch module can take other forms, for example, a circuit including a voltage comparator and field-effect transistors. Furthermore, the switch module 644 is not necessarily realized by circuits, and it can be realized in a mechanical manner. For example, a single-pole, double-throw switch can be coupled between the first input node 641, the second input node 643, and the voltage input pin of the packaged DC-DC voltage converter, and which can be switched to the first input node 641 or the second input node 643 by a button or toggle provided outside the display device 61.

FIG. 9 shows a schematic drawing of a circuit for use with a data-source device according to an exemplary embodiment of the disclosure. In FIG. 9, by way of example, the circuit 94 is used with a data-source device 90. As shown, the circuit 94 includes a first output node 941 coupled to a first connector 99, wherein the first port 99 is isolated from a data port 92 of the data-source device 90.

In operation, the first output node 941 of the circuit 94 is coupled to a display device 91, for example, a LCD, a plasma display, etc., via power-supply wires 991 to provide the display device 91 with a first direct voltage, wherein the wire 992 is grounded to provide a reference voltage. The first direct voltage is used for a real-time display of the data transmitted via the data wires 921 . . . 922 on the display device 91. The power-supply module 93 of the display device supplies power for the controller 95 and, under the control of the controller 95, supplies power for the data-receiving module 96, the signal-processing module 97, the display module 98, and the backlighting module 910. The data-receiving module 96 receives data to be displayed from a data port 92 of the data-source device 90. Depending on the data format, the data port 92 may be a HDMI Port, or a DP Port, a VGA port, etc. The data can be transmitted to the data-receiving module 96 via multiple data wires 921 . . . 922. The data-receiving module 96 typically includes a decoder to decode the received data and to obtain a video signal, audio signal, and synchronizing signal. The signal-processing module 97 typically includes a scaler, receives a video signal from the data-receiving module 96, and converts the video signal into a format suitable for displaying on the display device 91.

Specifically, the first input node 941 may be coupled to, for example, an output node of the power module of the data-source device 90 to obtain a direct voltage of 12V or 5V. The direct voltage is used for a real-time display of data obtained from the data-source device 90 on the display device 91.

FIG. 10 shows a schematic drawing of a circuit for use with a data-source device according to another exemplary embodiment of the disclosure. In comparison with the circuit of FIG. 9, the circuit 94 of FIG. 10 further includes an overcurrent-protection apparatus 104, coupled between the first output node 941 and the first port 99, so as to provide overcurrent protection for the first output node 941 when the first output node 941 is short circuited, or when an overcurrent is otherwise drawn. The overcurrent-protection apparatus 104 can take any suitable form, for example, a fuse element.

Embodiments of circuits for use with display device and circuits for use with data-source device have been described in the foregoing. And embodiments of a method for supplying power to a display device are described with reference to circuits. On the basis of the disclosure, combinations of, or modifications on, the embodiments which fall within the scope of the disclosure can be made, for example, the circuits shown in FIGS. 11 and 12.

FIG. 11 shows a combination of the circuit of FIG. 2. The display device 21 generally requires multiple operation voltages, for example, 3.3V, 2.5V and 1.8V. The power-supply module 23 may include multiple circuits 24, each including a first input node 241 coupled to the first port 201 of the data-source device 20 to receive a first direct voltage which is shown as 12V in FIG. 11. By changing the duty ratio of the control signal on the switch 51 of each circuit 24, the multiple circuits 24 have different output voltages, shown as 3.3V, 2.5V and 1.8V in the figure.

FIG. 12 shows a modification on the circuit of FIG. 2. The circuit 24 is configured to be a multi-level output converter.

In the disclosure herein, operations of circuit embodiment(s) may be described with reference to method embodiment(s) for illustrative purposes. However, it should be appreciated that the operations of the circuits and the implementations of the methods in the disclosure may be independent of one another. That is, the disclosed circuit embodiments may operate according to other methods and the disclosed method embodiments may be implemented through other circuits.

It will also be readily understood by those skilled in the art that materials and methods may be varied while remaining within the scope of the present disclosure. It is also appreciated that the present disclosure provides many applicable concepts other than the specific contexts used to illustrate embodiments.

From the foregoing it will be appreciated that, although specific embodiments have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the disclosure. Furthermore, where an alternative is disclosed for a particular embodiment, this alternative may also apply to other embodiments even if not specifically stated. 

1.-16. (canceled)
 17. An apparatus, comprising: a data port configured to provide data to a device; and a power port separate from the data port and configured to provide a power signal to the device.
 18. The apparatus of claim 17 wherein the data includes display data.
 19. The apparatus of claim 17 wherein the power signal includes a DC voltage.
 20. The apparatus of claim 17 wherein the power port is configured to provide a reference signal to the device.
 21. The apparatus of claim 17, further comprising a connector that is coupled to the data and power ports.
 22. The apparatus of claim 17, further comprising: a first connector coupled to the data port; and a second connector coupled to the power port.
 23. The apparatus of claim 17, further comprising a power supply coupled to the power port and configured to generate the power signal.
 24. The apparatus of claim 17, further comprising an overcurrent circuit coupled to the power port and configured to limit a current drawn by the device.
 25. An apparatus, comprising: a data port configured to receive data from a device; and a first power port separate from the data port and configured to receive a first power signal from the device.
 26. The apparatus of claim 25 wherein the data includes display data.
 27. The apparatus of claim 25 wherein the power signal includes a DC voltage.
 28. The apparatus of claim 25 wherein the power port is configured to receive a reference signal from the device.
 29. The apparatus of claim 25, further comprising a connector that is coupled to the data and power ports.
 30. The apparatus of claim 25, further comprising: a first connector coupled to the data port; and a second connector coupled to the power port.
 31. The apparatus of claim 25, further comprising a power supply coupled to the power port and configured to generate at least one supply signal from the power signal.
 32. The apparatus of claim 25, further comprising: a second power port separate from the data and first power ports and configured to receive a second power signal from a source other than the device; and a selector coupled to the first and second power ports and configured to select one of the first and second power signals.
 33. The apparatus of claim 25, further comprising: a second power port separate from the data and first power ports and configured to receive a second power signal from a source other than the device; a selector coupled to the first and second power ports and configured to select one of the first and second power signals; and a power supply coupled to the selector and configured to generate at least one supply signal in response to the selected one of the first and second power signals.
 34. The apparatus of claim 25, further comprising: a second power port separate from the data and first power ports and configured to receive a second power signal from a source other than the device; a selector coupled to the first and second power ports and configured to select one of the first and second power signals, the selector including an output node, a first diode coupled to the output node and configured to receive the first power signal, and a second diode coupled to the output node and configured to receive the second power signal; and a power supply coupled to the output node of the selector and configured to generate at least one supply signal in response to a signal provided by the output node of the selector.
 35. A system, comprising: a first apparatus, including a first data port configured to provide data; and a first power port separate from the data port and configured to provide a power signal; and a second apparatus, including a second data port coupled to the first data port and configured to receive the data; and a second power port separate from the second data port, coupled to the first power port, and configured to receive the power signal.
 36. The system of claim 35 wherein: the first apparatus includes a processor; and the second apparatus includes a display.
 37. The system of claim 35, further comprising a cable having a first connector coupled to the first data and power ports and having a second connector coupled to the second data and power ports.
 38. The system of claim 35, further comprising: a first cable having a first connector coupled to the first data port and having a second connector coupled to the second data port; and a second cable having a first connector coupled to the first power port and having a second connector coupled to the second power port.
 39. The system of claim 35, further comprising a cable having a first connector coupled to the first data port, a second connector coupled to the first power port, a third connector coupled to the second data port, and a fourth connector coupled to the second power port. 40.-41. (canceled)
 42. A method, comprising: providing data to a first apparatus from a data port of a second apparatus; and providing power to the first apparatus from a power port of the second apparatus that is separate from the data port of the second apparatus.
 43. The method of claim 42 wherein: providing data includes providing the data to a data port of the first apparatus; and providing power includes providing the power to a power port of the first apparatus that is separate from the data port of the first apparatus.
 44. The method of claim 42 wherein the data includes display data and the first apparatus includes a display.
 45. A method, comprising: receiving data from a first apparatus with a data port of a second apparatus; and receiving a first power signal from the first apparatus with a first power port of the second apparatus that is separate from the data port of the second apparatus.
 46. The method of claim 45, wherein: receiving data from the first apparatus includes receiving data from a data port of the first apparatus; and receiving the first power signal from the first apparatus includes receiving the first power signal from a power port of the first apparatus that is separate from the data port of the first apparatus.
 47. The method of claim 45, further comprising: receiving a second power signal from a source other than the first apparatus with a second power port of the second apparatus that is separate from the data and first power ports of the second apparatus; selecting one of the first and second power signals; and generating at least one supply signal for the second apparatus in response to the selected one of the first and second power signals. 